Edinburgh University scientists have managed to prove for the first time that hormones produced inside the womb play a pivotal role in the early stages of pregnancy.

It was previously thought this was only carried out by hormones made elsewhere in the body, which circulate to the womb through the bloodstream.

The research, published in the journal Scientific Report on Thursday, found specific hormones known as androgens help to prepare the womb lining.

As fewer of these hormones are produced as women age, this could partly explain why some older women find it difficult to conceive. It is also hoped the findings will help improve fertility therapies.

In the Medical Research Council-funded study, the team studied womb tissue donated by women who were already undergoing surgery for gynecological conditions.

They found androgens in the womb work with other hormones to help to make the womb lining ready to receive a fertilised egg.

Every month, the structure of the womb lining – known as the endometrium – is reorganised to create an environment that can support and sustain pregnancy.

Without the right hormonal signals, the endometrium will not provide the conditions required for a fertilised egg to implant.

By identifying the key hormones that control this process, the study could also help explain why IVF often fails when a fertilised egg is placed into the womb, the team said.

Dr Douglas Gibson, of the Medical Research Council Centre for Inflammation Research at Edinburgh University, who led the study, said: “The research is at a very early stage but it has already improved our understanding of fertility. In the long-term we hope this will lead to more effective fertility therapies.”